Modern aircraft typically include flight deck displays comprising display screens to present information relating to operating status of various systems of the aircraft to cabin crew members, in particular to a pilot and/or a co-pilot. Such information is typically provided during the various operating phases of the aircraft, for example, when the aircraft is on the ground, in a take-off phase, in an in-flight phase or in a landing phase. The various systems of the aircraft for which information is to be provided to the cabin crew members may have differing levels of criticality and may therefore take higher or lower importance and/or priority on the flight deck displays. Aircraft engines may be classified as one of those critical systems. As a result, multiple indications relating to the operation and/or operating status of the aircraft engines are typically presented to the cabin crew members via the flight deck displays.
Various flight deck display layouts have been developed to present the multiple indications relating to the operation and/or operating status of the aircraft engines such as, for example, a display screen 100 illustrated at FIG. 1. In some instances, the display screen 100 may also be referred to as a primary engine display. The display screen 100 displays information relating to two aircraft engines in a display portion 150 of the display screen 100. The information relating to a first engine is laid out so as to be displayed in a first longitudinal half of the display portion 150. The information relating to a second engine is laid out so as to be displayed in a second longitudinal half of the display portion 150. In some instances, the display portion 150 may have different shapes and/or dimensions so as to accommodate the display of additional information relating (or not) to the aircraft engines. In the example of FIG. 1, the display screen 100 displays values of various aircraft engine parameters such as parameter values 102, 122 associated with a low pressure compressor shaft rotation speed (N1), parameter values 104, 124 associated with an exhaust gas temperature (EGT), parameter values 106, 126 associated with an intermediate compressor shaft rotation speed (N2), parameter values 108, 128 associated with a fuel flow (FF(PPH)), parameter values 110, 130 associated with an oil temperature (OIL TEMP) and parameter values 112, 132 associated with an oil pressure (OIL PRESS). In some instances, the parameter values may also be associated with a graphical icon, such as the parameter values 102, 122 and parameter values 104, 124. The graphical icon may include, for example, a gauge or a portion of a gauge. In some instances, the display screen 100 may also provide access to multiple pages, each one of the pages including one or more parameter values and/or graphical icons.
A conventional approach, as the one illustrated at FIG. 1, requires the flight crew members operating the aircraft to view the parameter values, integrate the parameter values, interpret the parameter values and determine whether the parameter values warrant an action. In addition, the flight crew members not only have to determine that action is required but also have to determine which action amongst multiple actions is required. As an example, the flight crew members may determine that an abnormal start of one of the aircraft engines is occurring based on an interpretation of one or more parameters values. The flight crew members then have to determine which action is required such as, in the example of the abnormal start of one of the aircraft engines, entering a command to shut down the one or more of the aircraft engines.
To address this situation, various approaches have been proposed such as the one depicted in U.S. Pat. No. 7,148,814 to The Boeing Company (the '814 patent). The '814 patent describes a method of and a system for displaying an icon that represents an overall operational state of an aircraft engine. The method also includes directing a change in a displayed characteristic of the icon when the overall operational state of the aircraft engine changes from a started state and an unstarted state and vice-et-versa. The method includes relying on received engine operating parameter signals. The overall operational state of the engine is then determined based on the parameter signals. As an example, an indication that the engine is operating normally can be based on a determination that all the engine operating parameters are within an acceptable range of values and a determination that the engine is operating improperly can be based on a determination that any one of the operating parameters is outside the relevant acceptable range of values. Even though the method and system of the '814 patent may provide improvements in certain conditions, it does present limits, in particular for aircraft including certain types of aircraft engines such as, but not limited to, high bypass ratio aircraft engines.
The high bypass ratio aircraft engines such as, but not limited to, the PurePower PW1500™ from Pratt & Whitney or the Leap-X™ from CFM International may include specific design particularities. Such specific design particularities may result in parameter signals associated with the operation of the one or more engines having different behaviors than parameter signals of aircraft engines of previous generations. Such specific design particularities may include, but are not limited to, specific starter air valve performances and/or specific starter performances. In view of these particularities, improvement to existing methods and systems for displaying icons indicative of an operational state of an aircraft engine is desirable.